Buoyant motivational objects or toys have been known for many years. They are used in a great variety of water games that are played with children and dogs alike. They also play an important role in the training of working dogs for hunting or even search and rescue. One example of a buoyant motivational object is the “dog training device” described in German patent DE 103 23 763 A1. This device consists of a floating body in the form of an ellipsoid that has a consistency less dense than water. Each of the two opposite longitudinal ends of the device has a rope with a spherical weight on its outer end attached to it. The spherical weights ensure that the floating dog training device always lies flat in the water with its central axis parallel to the horizontal water-surface. The shape and floatation of this dog training device is intended to encourage a hunting dog to grasp the device in the middle which is desirable when teaching a dog how to correctly retrieve (e.g., a hunted duck from the water). If the dog would grasp the device on one of the outer ends, the weights would make retrieval of the device more difficult both in water and on land. In addition, the particular geometry of the aforementioned dog hunting device is intended to break the dog's habit of shaking its coat after leaving the water with the retrieved device. If the dog would follow its instinct to shake the remaining water of its coat, the weights attached to the ropes would impact against its head, muzzle or chest. To prevent this unpleasant sensation, the dog will learn to suppress its instinct to shake off until after the training device is released from the animal's mouth.
One drawback to this training device is the fact that it is difficult to identify by the dog while the object is in the water. The eyes of a swimming dog are only slightly above the surface of the water and this makes it rather difficult for the dog to detect the dog training device in its shallow floating position. Even with only slight waves in the water, the dog effectively loses sight of the training device. This often ends in the loss of an unrecovered device, which is both expensive and a very frustrating training experience for the dog.
In addition, there are many non-floating training objects that have been used. Examples include U.S. Pat. No. 3,830,202, DE 298 19 615 U1, or DE 299 17 816 U1. These non-floating objects exist in many different variations. They come in shapes and materials tailored to their particular purpose. Sometimes they are also made of materials with lower density than water to allow them to stay afloat in the water, even if that is not the primary purpose of that particular device. The devices illustrated in the above three references have a similar limitation; the objects may be difficult for a dog to recognize while the object is floating in the water. As a result, using this kind of device in or near water bears substantial risk device loss and a frustrating training experience for the dog.